Rotary steam-engine.



No. 65l,86l. Patented lune l9, I900. J. B. KELLY.

ROTARY STEAM ENGINE.

(Applicz atien filed Oct. 21, 1899.)

4 Sheets-Shae: I.

(No Model.)

wiweoozo No. 65|,86l. Patented lune l9, I900. J. B. KELLY.

ROTARY STEAM ENGINE.

. (Application filed Oct. 21, 1899.) (No Model.) 4 Sheets-Sheet 2.

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'No. 65l,86|. Patented June I9, 1900.

- J. B. KELLY.

ROTARY STEAM ENGINE. (Application filed Oct. 21, 1899.) (No Model.) 4 Sheets-Sheet 3.

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J. B. KELLY, ROTARY STEAM ENGINE. (Application filed Oct. 21, 1899.) 1 (NoModeL) 4'Sheats-S heet 4.

Suvemiioz V LEA/2 5/%// A m UNIT D STATES- PATENT OFFICE.

JOHN B. KELLY, OF PORTLAND, OREGON, ASSIGNOR OF ONE- HALF TO CHARLES L. VAN BUSKIRK, OF LODI, CALIFORNIA.

ROTARY STEAM-ENGINE.

SPECIFICATIONforming part of Letters Patent N 0. 651,861 dated Julie 19, 1900.

Application filed October 21, 1899. Serial No. 734,328. (No model.)

To rtZZ whom/it may concern.-

Be it known that I, JOHN B. KELLY, a citizen of the United States, residing at Portland, in the county of Multnomah and State of Oregon, have invented certain new and useful Improvements in Rotary Steam-Engines; and I do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

The invention relates to rotary steam-engines. y

The primary object of the invention is to provide a light-running engine which will transmit a maximum amount of power at a minimum expenditure of steam and which shall be of such construction that the expansive force of the steam within the cylinder will be direct upon the piston in a rotary direction and not radiallyupon the drive-shaft, thereby lessening the friction between said shaft and its bearing, and thus securing a greater rate of speed for a given expenditure of steam.

Another object is to provide a positive and automatic valve mechanism for admitting the steam to and exhausting it from the engine.

A further object is to provide a novel form of reversing mechanism.

With these and other objects in view the invention consists in certain features of construction and combination of parts, which will be hereinafter fully described and claimed.

In the accompanying drawings, Figure 1 is a perspective view of my improved rotary engine, taken from the impact-head-actuatingmechanism side of the cylinder. Fig. 2 is a similar view taken from the valve-mechanism side. Fig. 3 is a transverse section through the cylinder-casin g. Fig. 4 is a longitudinal section on the line 00 ac of Fig. 3 with the shaft shown in elevation. Fig. 5 is a horizontal section on the line y y of Fig. 3 looking upwardly. Fig. 6 is an enlarged detail elevation of the governor mechanism. Fig. 7 is an enlarged detail longitudinal section of the piston. Fig. 8 is an enlarged detail view of one of the piston packing-plates. Fig. 9 is a transverse section on the line 2 z of Fig. 7. Fig. 10 is a de tail perspective view of one of the rotating impact-heads. Fig. 11 is a similar view of the same. Fig. 12 is a detail perspective view of .the separated parts of the valve-reversing mechanism. Fig. 13 is a fragmentary side elevation of the reciprocating valves and their connecting-yoke, showing valve casings or chestsin section. Figs. 14, 15, 16, and 17 are diagrammatic views of respectively the forward opening segmental gear, the stopping segmental gear, the reverse opening segmental gear, and the closing segmental gear for actuating the impact-heads, showing the relative position of the gears to each other when secured to the shaft and their relative position to the piston.

In the drawings, 1 denotes the base of the engine; 2, the annular steam-cylinder, provided at its sides with impact-head chambers 3 and 3'. The removable front plate 4 of the cylinder is provided with ofisets 5 to form covers for said chambers; The outer faces of these covers are provided with T or three-way valve-casings 6 6", while the inner faces are provided with segmental guide-blocks '7, each of which projects inwardly entirely across the steam-space in the cylinder, but leaves a space 8 between it and the curved wall of the chamber. The T or three-way valve, as well as the guide-block, may be cast integral with the offsets 5 and are so shown.

9 9' denote annular ducts formed in the interior wall of the branches 1) and a of each valve-casing, and 10 and 11 denote ports communicating with said ducts and the steamspace of the cylinder.

0 and D denote the inlet branches or nipple of the valve-casings. These nipples are connected with the branches of a steam-supply pipe and are provided with inlet-orifices e and f.

12 and 13 denote impact-heads located in their respective chambers 3 3. Each head consists of a disk 14, a ring 15, and a curved face 16, connecting the disk to the ring. The

{disk end of the impact-head seats in a circular recess 17, formed partly in the rear wall of the steam-cylinder and partlyin the rear wall of the chamber, and the ring end seats in an annular groove 18, formed partly in the front wall of the steam-cylinder and partly in the front wall or cover of the impact-chamher. The curved face is adapted to rotate through the space 8 and across the steam-pas sage in the cylinder and is provided witha steam-duct 19,which leads to a similar duct in the disk. The duct 20 comm unicates-with an exhaust-pipe 21, whichextends through the rearwall of the chamber.

22 denotes circular webs,which may be continuationsof the inner annular wall ofthe steam cylinder. 23 denotes a drive-shaft which extends through the said webs and is journaled in the pillow-block bearings 24 25 denotes an annular slot formed in the inner wallof the steam-cylinder, and 26 denotesannular seats formed along the sides of the said slot to receive and seat a continuous annular metallic band or ribbon 27, which closes said slot. 28 denotes an arm keyed to said driveshaft and extending through the slot 25. The outer end of said arm is provided with an eye 29 to receive said band or ribbon27 to permit of, the rotation of the arm without disturbing the band or ribbon.

30 denotes a piston,square in cross-section to conform to the cross-sectional area of the steam-cylinder and curved longitudinally to correspond to the circularity of said cylinder. The piston is provided with a recess 31 in its inner-side, into which extends the extreme upper end oft-he arm 28. -A'pin 32 passes through the sides of the piston and the arm, thus pivotally connecting the parts together to permitof a slight movement of one independently of the other. The piston is preferably provided with grooves near its ends to receive the packing-blocks 33, which are held against the four walls of the steam-cylinder by the coil-springs 34, Placed in said grooves and arranged to break joint with the meeting ends of the packing-blocks are packingstrips 35. A piston thus constructed maintains a steam-tight joint with the walls of the steam-cylinder and automatically expands to take up any wear between the parts.

-Having thus described the construction of the steam-cylinder, its piston, andv the impact-heads, I will now proceed with the description. of the valves for admitting the steam to and exhausting it from the engine. 36 denotes a cam-yoke provided on its opposite sides with valve-stems 37 and 3S,-the former projecting into the branch a of the valve-casing 6 and being provided with valveheads 39 and 40. The valve-stem 38 projects into the casing 6 and is provided with valveheads 41 and 12. Assuming the valves to be in the position shown in Fig. 13 and the steam under pressure in the casings 6 and 6 the steam in casing 6 being confined between the valve-heads 39 and 40 and these valves being to one side of the duct 9, steam cannot enter the cylinder through the port 10, while, on the other hand, the valves 41 and 42, being on opposite sides of the duct 9,

permit the steam passing through the port e head touches said point. .13 now remains stationary in its position ing around toward the impact-head 12.

ton reached the point Z.

thesteam is admitted to the engine'throug'h theportll is in the position shown .in dotted lines in Fig. 3, and both the impact-heads are arranged across the steam-space of the cylinder. The piston is now forced around in the direction of the arrow, and when its forward end reaches the point in the circumference oft'he cylinder the impact-head 13 begins to rotate and turns from its position across the steam-space of the cylinder three-quarters of a-revolution or to the position shown in full lines in said figure, while the forward end of the piston is advancing to the point Z to per unit of the free passage of the piston. While extending across the steam-space and while the piston was advancing, the duct 19 was communicating with the steam-space, so that any water of condensation or air. driven in advance of the piston would pass through said duct 19 into the duct 20 and escape through the pipe 21. The impact-head 13 remains stationary while the front end of the piston is moving from the point I and until the rear end has reached the point m. The head now resumes its movement and travels with the piston, the rearend of the piston passing the point at at the instant the impact- The impact-head across the'cylinder while the piston is movthevalves 39, 40, 41, and 42 were in the position to admit steam through the duct 9 and port 11 into the cylinder between the rear end of the piston and the impact-head 12 and itoc ut off the steam from said cylinder through the duct 9 and the port 10. When the rear end of the piston reached the point 7t, the valve 42 began to move toward the d not 9 and came to a point that completely closed said duct at the instant the rear end of the pis- During the time the rear end of the piston was passing from the point Z to the point n the steam was actingexpansively and the valve-head 42W3S passing over the duct 9 and the valve-head 40 was passing over the duct 9 toadmit steam through said latter duct at the rear end of the piston. At the instant the piston passes the'point n the duct 9 is quickly uncovered by the valve-actuating mechanism (hereinafter described) and a full head of the steam is admitted between the impact-head 13 and When the rear end of with the cylinder and the used steam begins to exhaust through said duct, thereby relieving the impact-head from pressure by the steam and allowing it to freely close. Now

at this instant the valve-head 39 has passed over the duct 9 and shut oif steam therefrom,

thus allowing the used or exhaust steam to pass from the cylinder through the port 11 and duct 9 out into the atmosphere. The piston continues its course around the cylinder from the point at under the pressure of the steam admitted through the duct 9 and port 10 and forces any water of condensation or air through the ducts 19 and 20 of the impact-head 12 out through the pipe 21 to the atmosphere. As the piston approaches the impact head 12 the same operation takes place at this point as set forth in the description of the operation of the impact-head 13, and asit passes said impact-head the valves are shifted back to the position shown in Fig. 13.

I will now proceed to describe the valve shifting or regulating mechanism hereinbefore referred to, and while I prefer to employ the same in connection with my engine and have shown it in detail and have made it the subject-matter of a separate application filed herewith, Serial No. 734,329, I do not wish to be confined to this particular form of shifting mechanism, as I contemplate using other forms of regulating mechanism.

The valve-regulating mechanism consists of a cam-yoke 36, from the sides of which project the valve-stems 37 38, the former projecting into the valve-casing 6 and carrying the valves 39 40 and the latter projecting v i I into the valve-casing 6 and carrying the valves 41 42 to open and close the ducts 9 9 that lead to the engine-cylinder, the governorweight 54, the variable valve-shifter 49, the pinion-hanger 48, pinion 50, with its pinionstud 52, the positive valve-shifter 47, the lock 45, the lock-pin 51, and several minor details hereinafter described.

The lock. preferably consists of a ring 45, keyed to the drive-shaft of the engine and provided with a collar 45", and a head 45, having hooks 45 and 45 in the bills of which are formed notches 45 and 45 The positive valve-shifter preferably consists of a plate 47 having an elongated aperture 47 This plate is supported upon the collar 45 of the ring 45 by a bow-spring 46. On the periphery of the plate 47 is an overhanging shifting head 47", provided with a curved working face 47 and a transverse aperture 47. In the front face of the plate, at a point opposite the shifting-head, is formed a notch 47 for a purpose hereinafter to appear. w

The pinion -hanger 48 consists of a ring placed on the drive-shaft in advance of the plate 47 and provided with an apertured ear 48'.

The variable valve-shifter 49 consists of a ring 49 placed upon the drive-shaft in advance of the pinionhanger and provided on its front face with a circular rack 49" and on its periphery with a shifting-head 49, having a curved overhanging shifting-face 49, which projects toward the plate 47 and travels under its overhanging shifting-head.

A stop-collar 55 is secured to the shaft by a set-screw 55 and prevents the parts confined between il: and the lock 45 moving lengthwise of the drive-shaft.

The governorweight 54 preferably consists of a ring 54, having projecting from its periphery a weighted head 54, provided in its face with an apertured ear 54. To the rear face of the head 54 is secured a curved rack-bar 54 which meshes with the pinion 50. Projecting from the periphery of the ring, at a point opposite to the weighted head, is an overhanging perforated lug 54 to receive the lock-pin 51,which is provided with aperforated head 51. This pin passes loosely through the lug to permit of a free swinging movement of the governor-weight and is driven tightly through the aperture 47 of the plate 47, so that it will not become accidentally disengaged. The extreme rear end of the pin engages one of the hooks of the head 45 of the lock-ring 45 and projects slightly beyond-the same.

56 denotes a coil-spring loosely encircling the drive-shaft and provided with two oppositely-projecting arms 56 and 56 the former of which projects through the perforated head 51 of the lock-pin 51 and the latter of which projects through the perforated lug 54 of the weighted head 54. To vary the force of the governor-weight acting against the spring 56, I provide said weight with screwthreaded apertures 54 to receive the threaded weight-plugs 54 To increase the weight of the governor-head against said spring, the plugs are screwed into the governor-head. To lessen the force, the plugs are removed. By referring to the drawings it will be noticed that the aperture in the plate 47 and the ring 54 have diameters greater than that of the shaft to permit of a free axial movement of the plate and ring with respect to the shaft. It should also be borne in mind. that the ring 49 is not keyed to the shaft, and while ithas no axial movement with respect to the'shaft it is free to turn thereon.

IIaving described the construction of the valve regulating or shifting mechanism, I will now proceed to describe the manner in which the steam is admitted to the cylinder and exhausted from the same by the said mechanism.

Taking eighty revolutions a minute to be the desired speed. at which the engine is to be run and to be cut off at three-fifths of every half-revolution when working under a given load and a given head of steam, the

engine is started by admitting the steam to shifter in its revolutions around with the ent a v 651,861

until the desired speed is reached, When the engine is first set in motion and until it gains a sufficient speed to affect the steamregulating mechanism, the valves are shifted to their full movement by the positive valveshifter, which in its revolutions around with the shaft within the cam-yoke engages said yoke at a point marked 00' y toward the latter end of each half-revolution ofthe piston and begins to. move the yoke and valve=heads in the direction of the port toward which the piston is moving. Now when the valveshifter: has reached a point'on the cam-yoke marked y the piston is at that moment in a position to start on the second half-revolution, and at this point the port is quickly uncovered by the action of the positive valveshifter, acting against the bulged face 2, (seen opposite the valve-stem on the inner surface of the cam-yoke,) thereby admitting the live steam to the second port and allowing the used steam to be exhausted'from the cylinder back through the first port. The ports now remain wide openone to admit steam to the cylinder and the other to exhaust the tion in likemanner and with like results as Now when the speed of the engine before. has increased sufficiently-to aflect the steamregulating mechanism, then the governorweights, acting against the coil-spring, cause it to give way and to allowthe curved rack to swing backward and to rotate the pinion, and that in turn rotates the circular rack and variable valve-shifter, the latter moving around toward the way the engine is running. When the variable valve-shifter has moved out from under the positive valve-shifter and advancing ahead of the latter, said valveg'ine engages the cam-yoke in advance of the positive valve-shifter and being shorter and traveling on a shorter radius moves the valves to such a position that the valve-heads rest directly over the ports to the cylinder,cutting off all the steam from the cylinder and allowing the engine to move under the expansion of the steam contained in the cylinder to the end of the half-revolution, when the positive valveshifter engages the cam-yoke and moves the valves to a full-open position, as has beendescribed. As the speed of the engine increases the greater will be the force exerted against the coil-spring by the governor-weights, thus allowing the curved rack to swing farther back andlikewise to move the variable valveshifter farther in advance of the positive valve-shifter, and to cutoff the steam earlier until the engine is running at eighty revolutions and cutting of at three-fifths when working as before specified. Now if for any reason the load of the engine should be increased or the steam-pressure should be decreased, thereby causing the engine to move slower, the'governor-weig'hts would then act with less force against the coil-spring, and the curved rack would be drawn forward by the tension of the partially-released spring, and the variable valve-shifter would be drawn back, thereby eifecting a later cut off; but if, on the other hand, the load of the engine should be decreased or the steam-pressure should be increased, thereby causing the engine to run faster than desired, the force of the governor-weights would be increased and cause the curved rack to swing farther back and to draw the variable valve-shifter farther ahead and to cut off the steam earlier until the governor-weight ring was brought to arest against the shaft. should continue tg increase, the bow-spring 5 will be compressed and allow the positive F valve-shifter to drop down toward the same radius in which the variable valve-shifter is Then if the speed traveling, and thus to shorten the movement of the valves until both valve shifters are traveling in the same line and the valves closed over the ports in the valve-chest, thus cutting off the steam for the entire'revolution of the engine-piston. Should now the force exerted against the governor be so great as to compress the bow-spring still farther, as in the case of an accident, such as theparting of the main belt while the engine was under a full head of steam, thus causing the engine 1 to lunge forward with a jerk, then the lockpin'will move down and engage the notch 45 of the lock and lock the head of the positive valve-shifter to turn inv the same are as the head of the variable valve-shifter. The positive valve-shifter now being locked and the steambeing cut off, the engine will soon come to a stop.

I will now proceed to describe the mechanism by which the impact-heads are actuated and the mechanism for reversing the engine. Referring to Figs. 1, 4, 5, 14, 15, 16, and 17,

1 6O 61 denote two segmental pinions fixed to the pipe 21 of the impact-head 13, and 62 63 denote counterpart pinions fixed to the pipe 21 of the impact-head 12. These pinions are preferably in the form of spur-pinions, the

set 60 61 being blank at 60 61, respectively, and the set 62 63 being blank at 62 63 respectively. Splined to the drive-shaft of the engine to rotate therewith and slide thereon are what I will term for convenience of reference the forward opening 'segmentalgear 64:, designed to rotate the impact-heads threequarters of a revolution from point it (see Fig. 3) to a point m to open them, the stopping segmentalgear 65, designed to stop the engine previous to reversal, the reverse opening segmental gear 66, designed to rotate the impact-heads three-quarters of a revolution from point n to m Fig. 3, to open them after the engine has been reversed, and the closing segmental gear 67, designed to rotate the impact-heads a quarter of a revolution from the point 172 to the point it before the movement of the piston is reversed and a quarter of a revolution in the opposite direction from point m to point a after the movement of the piston has been reversed, in each case to close the impact-heads. The gear 67 is sleeved upon the hub 68, which carries the gears 64,

o 65, and 66, and is connected to said hub by a pin-and-slot connection 69, so as to have an independent limited rotary movement relatively thereto, and is connected to the en gineframe at 70 to prevent its longitudinal move ment on the drive-shaft. The gear 64 is preferably formed with pin-teeth 64 and with blank space 64. The gear is preferably formed with angular teeth 65 and a blank space 65 The gear 66 is preferably formed with pin-teeth 66 and blank space 66, and the gear 67 is preferably formed with the pin-teeth 67 and with the blank space 67. The relative arrangement of these several gears,,with the piston with which they travel, is clearly illustrated in Figs. 14, 15, 16, and 17,wherein the lines of the piston are conventionally shown in dotted lines. 71 denotes a shipperlever fulcrumed to the base of the engine, which engages a collar 72, formed on the outer end of the hub 68 and is adjustable and held at itsupper end in a rack 73. 74 denotes a second lever pivoted to the side of the engine and provided with inclined faces 74 and 74 and an intermediate notch 74. 75 denotes a spring for coaction with said lever.

The operation of the mechanism above described is as follows: As the engine is running in its forward movement and when the forward end of the piston has reached the point 76, (indicated in Fig. 3,) as hereinbefore described, the section 64 of the forward opening segmental gear engages the outer pinion 61 and moves the impacthead 13 around and out of the passage of the piston in the cylinder, having turned the outer pinion 61, so that its blank side faces section 64, and the forward opening segmental gear becomes disengaged and moves on without turning the impact-head 13 any farther. Then when the rear end of the piston has reached the point m the closing segmental gear 67 engages the inner sprocket 60, which has been turnedv so that its sprocket-section stands in .the path of said closing segmental gear and rotates the impact-head 13 one-quarter of a turn or down across the steam-cylinder. The piston and aforesaid opening and closing segmental gears keep a fixed relation to each other in the forward movement of the engine, so that when the piston has passed the impact-head 13 and moved around toward the impact-head 12 the same operation that has just been described in connection with the opening and closing of the impact-head 13 takes place at the impact-head 12. Now when it is desired to reverse the motion of the engine the engineer grasps the lever 74 in one hand and the lever 71 in the other hand. The lever 74 is brought down so that its inclined faces 74 74 stand across the path in which the lock-pin 51 is traveling. The force of the engine carrying the lock-pin forward against said inclined faces of the said lever 74 forces the pin downward and out of the lock-hook 45, in which it has been engaged, into the notch 74 in the cam-lever 74,in which it is held until the'lock has passed around and the opposite edge of its head 45 engages the lockpin. Then the cam-lever 74 is allowed to swing upward by the action of the spring 75 and out of the path of the lock-pin. Now the steam will be admitted to the forward end of the piston instead of the rear end. At this moment the hub 68 is slid out on the shaft until the stopping segmental gear 65 is brought'in line with the outer pinions 61 and 63. The stopping segmental gear now engages the said pinions 61 63 in such a way and at such a time in the movement of the piston that the impact-head toward which the piston is approaching will be turned with its concave side to the piston in a position to close the cylinder in front of the piston at the time the steam is admitted to the cylinder, thereby causing the steam to be caught between the impact-head and approaching piston, thus exerting a contrary force against the piston to stop it in its forward movement. If the force of the steam between the impact-head and forward end of the piston should not be sufficient to stop the engine, then the impacthead will be carried forward by the continued forward movement of the gear 65 and out of the way of the piston. The same stopping action will be repeated at the next impact-head, and so on until the engine is stopped. When the piston has been brought to a stop inits forward movement by the steam confined between the concaved face of one of the impactheads and the forward end of the piston, then the hub 68 is quickly shifted, so that the reverse segmental gear 66 is brought in line with the outer pinions 61 63. The section 66 in the reverse segmental gear having the same relation to the piston in its reverse movement as had the section 64 of the opening segmental gear in the forward movement of the piston the impact-heads will be opened in the same way as has been described in connection with the forward movement of the engine, while the closing segmental gear has changed sides in its relation to the piston and now moves in the rear of the piston in the reverse of the engine,the same as it did in the forward move ment of the engine, in a position to close the impact-heads behind the piston, as has been described.

Having thus fully described my invention, what I claim as new and useful,- and desire to secure by Letters Patent of the United States, 1s

1. Inarotarysteam enginemhecombination with an annular steam-chamber one of the walls of which is provided with an annular slot, said chamber being provided with inlet and exhaust ports, a suitably-mounted driveshaft, an arm carried by said drive-shaft and extending through said slot, a piston carried by said arm, a ribbon or band located within said chamberand closing said slot, said arm having a sliding engagement with said ribbon or band, and impact-heads having rotary movements across the path of movement of said piston within said chamber, substantially as and for the purpose set forth.

2. In a rotary steam-en gine the combination with an annular steam-chamber one of the walls of which is provided with an annular slot, said chamber being provided with inlet and exhaust ports, a suitably-mounted driveshaft, an arm carried by said drive-shaft and extending throughsaid slot, a piston carried by said arm, a ribbon or band located within said chamber and closing said slot, said arm having a sliding engagement with said ribbon or band, and im pact-heads having rotary with the annular steam-chamber provided with inlet and exhaust ports; of a rotary piston,-impact-heads provided with supplemental exhaust-passages, and means for rotating the impact-heads a complete revolution with variable movements at predetermined intervalsacross the path of movement of said piston in said chamber, substantially as and for the purpose set forth.

5. In arotary steam-engine the combination with the annular steam-chamber provided with impact-head chambers and with alternatelyacting inlet and exhaust .ports and with segmental guide-blocks; of valve-chests communicating with said ports, valves located in said chests, means for simultaneously actuating said valves, and'impaet-heads located in their respective chambers and provided with auxiliary passages, and means for rotating said impact-heads across the steamchamber, substantially as and for the purpose set forth.

6. The combination with a drive-shaft of a rotary steam-engine, impact-heads arranged to cross the path of movement of the enginepiston, shafts extending from said impactheads, segmental pinions on each shaft, a segmental opening gear carried by thedriveshaft and adapted to engage one set of the aforesaid segmental pinions and rotate the impact-heads from their position across the steam-space of the engine three-quarters of a revolution, and a segmental closing gear rotating with said shaft and adapted to engage the other set of the aforesaid segmental pinions and rotate the impact-heads onequarter of a revolution, substantially as and for the purpose set forth.

r 7. The combination with a drive-shaft of a 1 rotary steam-engine, impact-heads arranged to cross the path of movement of the enginepiston, shafts extending from said impactheads, segmental pinions on each of said shafts, a segmental opening gear carried by said drive-shaft and adapted to engage one set of pinions in the movement of the piston in one direction, a stopping segmental gear adapted to engage saidlast-named set of pinions in the stopping of the engine, areverse Esegmental. opening gear adapted to engage said latter set of pinionsin the reverse movement of the engine, and a segmental closing gear connected to the drive-shaft to turn therewith and to have a limited rotary movement f with respect to the same said segmental gear adapted to engage the other set of segmental pinions in either the forward orreverse movement of the engine, substantially as and for the purpose set forth.

In testimony whereof I have hereunto set my hand in presence of two subscribing witnesses.

JOHN B. KELLY. 

